分解因式 :x^3+6x^2+3x-10

问题描述:

分解因式 :x^3+6x^2+3x-10

x^3-x^2+7x^2-7x+10x-10
=(x-1)(x^2+7x+10)
=(x-1)(x+2)(x+5)

x^3+6x^2+3x-10
=(x^3+5x^2)+(x^2+3x-10)
=x^2(x+5)+(x+5)(x-2)
=(x+5)(x^2+x-2)
=(x+5)(x+2)(x-1)

x^3+6x^2+3x-10
x=1时,x^3+6x^2+3x-10=0,所以有
x^3+6x^2+3x-10
=x²(x-1)+7x(x-1)+10(x-1)
=(x-1)(x²+7x+10)
=(x-1)(x+2)(x+5)